This book analyses and evaluates Europe's experience with Early Warning System (EWS) which allows national parliaments to review draft legislative acts of the European Union for their compatibility with the subsidiarity principle. The EWS was introduced in response to the perceived 'democratic deficit' of the EU and its 'creeping' competences and represented one of the landmark reforms of the Lisbon Treaty. The purpose of this book is present and critically analyse the functioning of the new mechanism of subsidiarity review and the role that national parliaments have played within this...